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Excerpts from

The Quarrying Industry of Missouri

By E. R. Buckley, Director and State Geologist, and H. A. Buehler

Missouri Bureau of Geology and Mines Vol. II, 2nd Series, Jefferson City, Missouri,
Tribune Printing Company, State Printers and Binders, 1904.

Continued on Page 1 2 3 4 5 6 7

Table of Contents.
Letter of Transmittal IX.
Acknowledgements XI.
Introduction XIII.
Chapter I, Demands and uses 1
Chapter II, Necessary considerations in the selection of stone 8
Chapter III, The properties of stone used in building constructions and methods of determining same 30
Chapter IV, A brief geological history of Missouri 52
Chapter V, Pre-Cambrian (Granite and Rhyolite) 60
Chapter VI, Cambro-Ordovician 86
Part I - Limestone (dolomite) Quarries.* 
Part II - Sandstone Quarries.* 
Chapter VII, Silurian and known Ordovician* 106
Chapter VIII, Mississippian (Sub-Carboniferous)* 120
Chapter IX, Pennsylvanian (Coal Measures)* 211
Part I. - Limestone Quarries.* 
Part II. - Sandstone Quarries.* 
Chapter X. Areas from which stone suitable for different uses may be obtained 278
Chapter XI, Laboratory Tests 291
Chapter XII, Conclusion 327
Table showing production of stone in Missouri for 1903. Appendix. Composition and kinds of stone. Rock Structures 331

(* These sections will not be included in this document. You will find the individual quarries listed in these sections of the book in the “Missouri Stone Quarries” section of the web site.)

Letter of Transmittal.

“Bureau of Geology and Mines,

Rolla, April 10, 1904.

“To the President, Governor A. M. Dockery, and the Members of the Board of Managers of the Bureau of Geology and Mines:

“Gentlemen - I have the honor and pleasure to transmit to you a report of the Quarrying Industry of Missouri.

“The field work for this report was begun in the summer of 1902 and has been carried on, as opportunity would permit, up to the present time.  Mr. H. A. Buehler has examined all the important quarries in the State, giving special attention to those engaged in the production of stone for building and ornamental purposes.  I have examined the quarries in the more important districts alone and in company with Mr. Buehler.

“Not only have the quarries been examined, but buildings, monuments and pavements, constructed out of Missouri stone, have been examined, and samples of the stone have been tested in the laboratory.  Every important means, by which the durability of stone can be determined, has been used.

There are many small quarries, worked only to supply the local market, which have not been examined. It is impossible, however, to determine the names and locations of these quarries without spending several weeks in most of the counties of the State.  Therefore, this report has been devoted to a discussion of the most important and best developed quarries.*  It is thought that no quarry from which stone is shipped has been omitted from this report, while there have been included descriptions of many quarries which are worked solely to supply the needs of the community in which they are located.

“Careful statistics of production have been collected and compiled showing that this industry adds to the permanent wealth of the State over two and one-half millions of dollars a year.  It is expected that this repot will give the public information which will result in a much more extensive use of Missouri stone.

“That portion of the report embodying the descriptions of the quarries - Chapters V, VI, VII, VIII, IX and X - was written by Mr. Buehler.

“Mr. Buehler made most of the physical tests, made all the chemical analyses and prepared the maps and illustrations with the exception of the drawings accompanying the tables in Chapter XI.  The remainder of the report, including Chapters I, II, III, IV, XI, XII, the Introduction and the Appendix, was written by myself.

“I remain, very respectfully, your obedient sir,

“E. R. Buckley.”

(* Please Note:  The emphasis on the first part of this paragraph is mine and is not found in the book.  I want to point out that many quarries were not studied and so may not be included in the quarries listed in this book.  Peggy B. Perazzo)

* * * * * * *


“The successful completion of a report of this character depends very largely upon the interest manifested in the work by quarry owners and operators.  To all of these authors are under deep obligation for many courtesies extended.  We are indebted to the Universities of Illinois, Kansas and Wisconsin for the use of their laboratories in testing the samples of stone collected.  We also desire to extend our sincere thanks to Dr. J. H. Britts of Clinton, Sidney J. Hare of Kansas City, and Judge John L. Bogy of Ste. Genevieve for many courtesies.  Our thanks are also extended to the different railroad systems in the State for the very generous assistance which they have rendered.

* * * * * * *

“During the administrations of Winslow and Keyes, special reports were published on “Lead and Zinc,’ ‘Coal,’ ‘Mineral Waters,’ ‘Iron Ores’ and ‘Clay Deposits.’  Up to the present time, reports have not been published on the quarrying industry, the lime and cement industries, soils, road materials, barite and asphaltic limestone and sandstone.  This report deals with the quarrying industry.  It is the plan of the bureau to follow this with report on the ‘Lime and Cement Industries,’ and this in turn by other reports on resources that have not yet been investigated.  Later, it will be necessary to revise and publish new editions of the special reports which we now have.  These reports are thought to be the most valuable publications of the Bureau.  They bring together a vast amount of information which serves not only to educate the public at large, but also to attract capital seeking investments.

“To fully understand the characteristics of stone used for buildings and other constructions, one should be familiar with the composition and manner of occurrence of the common minerals and rocks.  In discussing the chemical, mineralogical, and physical tests of stone, it is often necessary to use terms with which the general public is not familiar.  In order to make this report more intelligible, an appendix has been added in which the composition and kinds of minerals and rocks, and the common rock textures and structures are discussed.

“The first three chapters of this report are devoted to a discussion of the demands and uses of stone, the necessary considerations in the selection of stone, the properties of building stone, and the methods of determining the value of stone for different uses.  Chapter Four is a brief geological history of Missouri.  The fifth, sixth, seventh, eighth and ninth chapters embrace a complete discussion of all the important quarries in Missouri, giving the manner of occurrence of the stone, its color, composition, strength, durability, etc.*  Chapter Ten is devoted to a discussion of the areas from which suitable stone for different uses may be obtained.  In this chapter it is not intended to point out the uses to which the stone in each individual quarry is suited, but rather to give a general idea of the wide distribution of good building stone in the State.  Chapter Eleven is devoted to a discussion of the physical tests, and contains tables showing the results of the laboratory examination of samples of stone from twenty-nine different quarries.  It is thought that this series of tests is very complete and that it will be especially valuable to architects and builders in the selection of stone to be used in the construction of important buildings.

(Please note that the quarries listed in Chapters 5, 6, 7, 8, and 9 will not be presented in this document.  You will find the entries pertaining to the individual quarries in the “Missouri Quarries Section” listed according to the location of each quarry. Peggy B. Perazzo)

“This report is accompanied by a geological map of Missouri on which the important quarries have been located.  The geology on this map has been reproduced from a map published in an earlier report of this Bureau.  This report also contains sketch maps showing the location of the quarries in the vicinity of St. Louis, Kansas City and Carthage.  The exact location of all the quarries can be obtained by reading the descriptions in the body of the report.  Half-tone cuts of some of the more important quarries and of the buildings in which Missouri stone has been used, constitute the chief illustrations on this report.  The reader can obtain a good idea of the size of the quarries and the adaptability of the stone to building constructions by examining these in conjunction with the descriptions of the various quarries.

Plate I.  A Geological Map of Missouri Showing the Location of the Principal Stone Quarries (1904), by H. A. Buehler, Missouri Bureau of Geology and Mines, E. R. Buckley, Director and State Geologist, 1904.  Geology based on Broadhead Map of 1873, and Keyes Map of 1896.  (Please note:  The following types of features  are shown on the map:  Limestone, Sandstone, Lime-kiln, Silica and Tripoli, and Granite and Rhyolite.) A Geological Map of Missouri Showing the Location of the Principal Stone Quarries (1904)
Plate XII.  Map Showing the Distribution of Quarries in the Granite District of Southeast Missouri, by H. A. Buehler, 1904, Missouri Bureau of Geology and Mines, E. R. Buckley, Director.  Geology based upon map by Erasmus Haworth in Vol. VIII. of the Missouri Geological Survey Reports. Map Showing the Distribution of Quarries in the Granite District of Southeast Missouri

“Several plates have also been inserted to illustrate the results of the laboratory tests.  It is interesting to know the manner in which different stones break, when subjected to a pressure greater than their ultimate strength.  Accompanying these plates are a number of photographs of thin sections of granite, sandstone and limestone, as seen through the microscope.  These illustrations give one an idea of the size and shape of the individual grains of which the different kinds of rock are composed.  Since the strength and durability of a stone depends chiefly upon its composition and texture, these illustrations are especially instructive.

“The quarries which are engaged exclusively in the manufacture of quicklime and cement have been given very little attention in this report.  It is the intention to publish a volume on the lime and cement industries in which these quarries will be fully described.

“Reliable statistics have been collected and compiled to show the value of the output of stone from Missouri in 1903.  This is very interesting in so much as it shows a production far above that reported by the United States Geological Survey.

“The people in this State have a very meager conception of the importance of the stone industry.  Very little is known in some parts of the State as to the value of the granite, limestone and sandstone which is shipped to all parts of the Mississippi valley.

“The red granite which is quarried in the southeastern part of the State has an enviable reputation among granite workers in this and neighboring states.  The consumption of this stone for monumental and building purposes in increasing, and it is thought that before many years it will replace almost entirely the eastern red granites which are now sold so extensively within the State.  The limestone and sandstone quarries are among the most important in the Mississippi valley.  The Carthage limestone is unexcelled as a building material by any limestone in the middle west.  In color it is unsurpassed and in strength and durability it is the equal, if not the superior, of any stone with which it comes into competition.  The other limestones which are being quarried supply an ever-increasing home market.  The sandstone quarries at Warrensburg and Miami produce stone which finds a ready market in the southern states and they constitute one of the valuable sources of sandstone in Missouri.

Plate II.  Red Granite.  Boulders resulting from weathering.  Graniteville, Mo. Red Granite. Boulders resulting from weathering

“The caves in the Ozark region contain large deposits of onyx which in some places may be suitable for interior decorative purposes.  It is not being exploited at the present time (circa 1902-1904), owing to the distance of the deposits from the railroads and the inferior quality of that which has thus far been quarried.

“In the vicinity of Seneca there are extensive and valuable deposits of Tripoli from which are produced water filters of superior quality.  The sandstone quarries at Pacific, Klondike, Gray’s, Summit and Silica produce sand or quartz which is unexcelled for the manufacture of glass.  The Burlington and Trenton formations consist of limestone which makes a quicklime of unsurpassed excellence.  The shale and limestone of the Carboniferous are in many places well suited to the manufacture of Portland cement.  In Vernon and other counties in the western part of the State there are extensive deposits of asphaltic sandstone, as yet undeveloped, which constitute a valuable source of material for paving.

“Altogether, the building stones of Missouri constitute one of her most valuable natural resources.  It is one which adds millions each year to her permanent wealth, and one without which she would suffer many inconveniences.”

* * * * * * *

Chapter I.

Demands and Uses.

“Among the least attractive and yet most valuable resources of a country are the products of the stone quarries.  Every city, town and village is made wealthier by the occurrence of stone which can be used in the ordinary, rough forms of masonry construction.  In some places the rock exposures are so numerous and the needs of the people in this direction so limited that no large quarries are developed.  The farmers during the winter months frequently haul stone into town, as they do wood, selling it for foundations, sidewalks and other purposes.  In the smaller towns the demand for stone, rough or dressed, is very limited and although good stone may be obtainable from the local quarries, it is often cheaper to purchase the same from a larger quarry located at a distance.

Stone is used for a multitude of purposes and it may be necessary only to mention a few of these to bring to the attention of the reader the importance of the quarrying industry.  A greater part of the stone quarried is used for constructional purposes, but an important part is used in conjunction with other materials for the production of which may be termed artificial or manufactured products.  The uses of stone in its natural state may be considered under the heads of Building, Bridge, Culvert, Paving, Concrete, Railroad ballast, Curbing, Engraving, Abrasives, Insulators, Ornaments, Filters, Furnace, Post, Fence, Retaining Walls, Breakwater, Monument and Miscellaneous.  Stone used for artificial products may be considered under Glass, Cement, Lime, Fertilizer, Pottery, Paint, Chemicals, gas, etc.”

Building Stone.

“Under ‘Building stone’ it is customary to include all stone used in buildings, public and private, of any description.  In most buildings the stone is cut and dressed before being used, although frequently, where the walls are concealed or the artistic feature is unimportant, the stone is used as quarried, being cut only by the mason for the purpose of fitting the pieces into the wall.  The walls of a building may be entirely or only in part constructed out of stone.  frequently the front is veneered with stone while the remainder is built out of brick, terra cotta or cement concrete.  In the larger cities one may observe long rows of what appear to be stone residences, which in reality have only their fronts veneered with stone.  In the cities the tendency has been to build the fronts of business blocks and residences out of stone and the back and side walls out of common brick.  In the rural districts and in the small towns and cities the tendency has been to construct the back and side walls out of rubble stone and the front out of pressed brick.  In either case, the purpose has been to make as attractive a front as possible at a minimum cost.

“Rubble stone is used very generally for the construction of foundations to buildings.  The steel frames of many of our large buildings rest on thick stone piers built out of footing stone.  The foundation courses above the ground are usually built out of dressed ashlar blocks, while those below are random rubble masonry.

“Of late years brick and cement concrete have in a measure supplanted stone for foundations, as well as for walls and other parts of building constructions.  But, in any case, it is only a change in the form in which the stone is used.  Brick and terra cotta are produced mainly from shale - an argillaceous stone which is too soft for building - while concrete is a mixture of cement and broken stone.  Whether it be brick or concrete, stone must ultimately be used in one shape or another.  Where the walls are of brick and terra cotta, cut stone is frequently used for the sills, caps and other parts of the building commonly known as the trimmings.  The roofs of buildings are being more generally constructed out of slate, tile and metal sheeting than ever before.  Wooden shingles are comparatively expensive today (circa 1904), and it will not be long, with the present rate of depletion of our forests, before they are altogether replaced by more permanent materials.  In the large cities the danger from fire has compelled the use of slate, roofing tile and other fire proof materials, even before the increased price of wooden shingles practically forced them out of the market.

“In the interior, stone is used mainly for decorative purposes.  The floors of many of our public buildings are built out of marble, slate or cement concrete.  Stair-cases, columns, wainscoting, wash basins, switch boards and many other interior constructions call for stone in one form or another.

“In many of the rural districts, in Missouri, brick is expensive on account of the cost of transportation.  As a result stone has been used for many purposes, such as chimney, fire places and ovens.

“It is evident from the above that in the construction of buildings, alone, there is a wide demand for stone.  The rapid advance in the price of lumber has increased the use of other and more permanent materials in nearly all avenues of building construction.  Soon, as a matter of economy, buildings everywhere distant from our pine forests, will be constructed out of stone, brick, concrete, terra cotta or some other permanent material in preference to wood.  As our population increases and civilization advances our people will erect better and more durable buildings.  In all this change or evolution through which we are passing the quarryman will be called upon to provide, in one form or another, an increasing quantity of stone.

“The wooden buildings in all our large cities are gradually being torn down, and their places are taken by substantial fire proof structures built of stone, brick, terra cotta, concrete and steel.  The home of the working man, as well as that of the capitalist, is now being built of stone, brick or concrete.  There may come a time when a residence built out of wood will be a luxury only to be enjoyed by the rich.”


“The demand for monuments, mausoleums and headstones keeps pace with our rapidly increasing population.  Millions of burial places are marked with slabs, columns or shafts of marble, limestone or granite.  The demand for building stone may fluctuate, but that for monuments increases with the advance of civilization.

“Each year the demand is for more durable material, and as a result marble and limestone are being gradually supplanted by granite, rhyolite and other igneous rocks.  People prefer a small, durable monument to one which is large and temporary.  The superiority of granite over all kinds of marble and limestone can no longer be questioned.  The lettering on marble slabs and columns in a climate such as ours, soon becomes illegible and all signs of the original polished surface are soon effaced.  The white glistening marble is more distasteful to the eye than the more subdued red and gray tints of the granitic rocks.  Marble monuments and slabs are now erected mainly in the rural districts where the relative permanence of different stones is little known.  Thousands of people who purchase headstones and monuments do not know any difference between marble and granite, only that the former is less expensive.

“Sandstone has been used in some localities for monuments.  This stone is seldom uniform in texture, weathering unevenly and usually more rapidly than marble or granite.  It can never be polished and for this reason is little used for monuments.

“The extent to which a particular marble or granite is used for monuments is determined very largely by its reputation.  The granite and marble of the old world have long held a high place in the estimation of our people and we do not wonder at the use of Scottish and Scandinavian stone for some of the best of our monuments.  The granites from Massachusetts, Vermont and Maine, have won a prestige in the markets through their past extensive use.  The New Englander and Scotlander alike, feel that any rock from their native hills is worthy of any praise that can be bestowed upon it.  They contain themselves with a knowledge of the place from which it has been quarried and are proud to have their last resting place marked by a column of granite from their native country.  The Scotchman does not always know a good granite from a poor one, but he loves his native land and every rock that comes from its moors and crags is dear to him.

“The granites and marbles of this country are as strong and durable as those from Europe.  The granite and marble of the central and western states is as strong and durable as that from New England.  No more beautiful red granite can be obtained in the country than that which is quarried in the southeastern part of Missouri.  The brilliant and subdued red colors are equal to those of the granite quarried in foreign countries or the eastern states.

“The history of this country is not being written in the newspapers and books of today, but in the buildings and monuments which are being constructed in our great cities.  Should our republic be destroyed, the records inscribed on monuments would furnish a large part of the history of our people.  A stone which will crumble and decay in a century is unfit for a monument of any character.  If we would erect more permanent monuments, to better preserve the history of a great people, they must be of granite, not limestone and marble.  The demand for stone for monumental purposes is constantly increasing; and with this demand should come an increase in the development of the granite quarries of this State.”

Road Materials.

“Stone is the most abundant, cheapest and most widely employed of all the materials used in street constructions.  It is used in the construction of macadam and stone block pavements; in concrete foundations for curbing; for gutters; for sidewalks; for crosswalks; for bridge abutments; for culverts and various other miscellaneous uses.

“Foundations to pavements usually consist either of sand and gravel, wood in the form of planks, broken stone, brick, stone blocks or concrete.  Wherever the foundation is broken stone, stone blocks or concrete, the materials from the quarry enter directly into the construction.  Broken stone is probably the most widely used of any of the material mentioned for foundations.  Both macadam and telford pavements are being used as the foundation to asphalt and brick pavements.  Partly worn out stone block pavements are occasionally taken up, turned and relaid to serve as a foundation for asphalt or some other of the common pavements.  Concrete is most commonly used as a foundation for asphalt, brick and stone block pavements.  A concrete foundation is usually 5 or 6 inches thick and is composed of about 85 per cent. of broken stone in pieces not less than 1 ½ inches nor more than 2 ½ inches in their largest diameter.  

“The surface of the pavements may consist of either macadam, granite block, brick, asphalt, wooden block or sundry other materials.  Macadam and granite block pavements consist almost exclusively of material furnished by the quarry.  Paving brick are made out of soft shale which can scarcely be considered a quarry product.  The surface of an asphalt pavement consists of about 10 per cent. of pulverized granite or quartzite, either of which must be obtained from the quarry.

“In some cities asphalt pavements are constructed out of a bituminous or asphaltic limestone or sandstone which is quarried the same as any other stone.  A limestone or sandstone which is suitable for this purpose should contain not less than 10 per cent. of bitumen.

Gutters are, as a rule, constructed either out of concrete or stone.

Curbing may be either stone, concrete or terra cotta.  Up to within the last few years, both the curb and gutter were usually constructed out of stone.  Lately (circa 1904), however, the stone has been in a measure replaced by cement concrete and terra cotta.

Sidewalks and crosswalks are constructed mainly out of stone, brick or concrete.  In some localities, wood is used almost exclusively.  Lumber, however, is becoming so costly, that stone, brick or concrete are found to be less expensive.

Culverts, hitching-posts and stepping blocks, all of which are classed as highway constructions, are in part built out of stone.

“Thousands of bridges and culverts are being constructed and reconstructed each year along the public highways, the stone for which must be furnished by private quarries.  The railroads are constantly building bridges and culverts, in the construction of which great quantities of stone must be used.

“To a greater or lesser extent, in the construction of bridge abutments, concrete is replacing the stone which was used almost exclusively a few years ago.  The use of concrete, however, simply calls for broken stone instead of stone blocks.  In the construction of bridges or culverts, either along the railroads or highways, there will be a constantly increasing demand for stone.

“The demand for permanent highway improvements has not advanced very rapidly except in the larger cities and towns of Missouri.  The methods of improving the rural highways have changed very little during the last twenty years.  It is true that the roads are worked, but the same repairs have to be made year after year and the road frequently remains almost impassable half of the time.  Farmers have contented themselves with hauling half a load, on account of the depth of the sand or the thickness of the mud.  At present (circa 1904), however, there seems to be an awakening among the people which is manifesting itself in the demand for permanent improvements to the highways.

“Everywhere throughout the State, where stone is accessible, it will eventually be quarried and crushed for the construction of macadam pavements.  Within the next decade hundreds of miles of roads in this State will be macadamized, requiring for these improvements hundreds of thousands of tons of crushed stone.  The cities, towns and villages are improving their streets and no matter what kind of pavement may be laid, the quarry will be required to furnish the stone which enters into its construction.

“In the construction of a macadam pavement, the hardest and most durable stone obtainable should be used.  All stone is not suited for macadam.  Rocks, which are soft, will pulverize under the horses hoofs, forming a fine dust during dry weather and soft mud during the wet months of spring and fall.  A stone used for macadam should be sufficiently hard to withstand abrasion and the composition should be such that it will furnish constituents suitable for cementing the fragments together.”

River and Lake Constructions.

“Each year great quantities of rubble stone are being used in the construction of piers, breakwaters and cribs along our navigable lakes and rivers.  As the rivers in this State are improved and the channels made more navigable, the demand for rubble stone will increase.  The stone which is used for these purposes should have a capacity to withstand the attrition of the waves and should be practically insoluble.”

Railroad Ballast.

“Railroad ballast consists, as a rule, either of crushed stone, gravel or burned clay.  Of these three materials, crushed stone is considered the most desirable.  With hundreds of miles of unballasted railroad tracks and many miles of projected lines in this State, one has positive assurances of a continued demand for stone for railroad ballast.”


“In connection with the construction and operation of furnaces, large quantities of limestone and quartzite are used.  The quartzite is mainly used in the form of ganister for lining the furnaces, while limestone is used as a flux”.


“Much of the material used as an abrasive is simply finely pulverized quartz or silica, which is obtained by crushing and pulverizing quartz rock, either vein quartz or quartzite.  The demand for this product of the quarry is relatively strong.

“Among the abrasives must also be included grindstones, whetstones and oilstones.  Grindstones and whetstones are simply sharp fine grained sandstones having a uniform texture.  Oilstones are mainly novaculite which has an exceedingly uniform fine grain.”


“Among the miscellaneous uses for which stone is quarried may be mentioned sand for mortar, filters and foundry purposes.  Fine grained, pure limestone is used extensively for lithographing.  Less pure varieties are used in the manufacture of whiting, polishing powder, and similar substances.  Quartzite, slate and shale are ground and used as paint pigments.  Crushed stone and cement are used in the production of artificial stone.  Soapstone is quarried for the manufacture of bath and laundry tubs, fire brick, stoves, hearthstones, mantles, sinks, griddles, slate pencils, foundry facings, paper making, lubricants, paint pigments, etc.  Slates, blackboards, billiard tables and many other useful articles are manufactured out of slate.”

Artificial Products in Which Stone is Used.

“Sandstone, limestone and quartzite are the principal stones used in the production of artificial products.  Sandstone and quartzite are pulverized or ground and used in the manufacture of glass, pottery and silica or sand brick.  In some instances the sand or silica used for these purposes is obtained form unconsolidated river or lake deposits which ordinarily would not be included under the head of quarries.  Limestone is used in the manufacture of cement, quicklime, fertilizers, carbon dioxide and other miscellaneous products.

“Gypsum, which is calcium sulphate, sometimes occurs in the form of stone and is quarried for the manufacture of plaster of paris.”

Chapter II.

Necessary Considerations in the Selection of Stone.

“Everywhere the attempt is being made to secure the very best materials that the money at hand can purchase.  Ignoring, for the purpose of discussion, the item of cost, by which the mass of people are so largely controlled in their purchases, the selection of any stone will be determined  (1) by its color and  (2) by the capacity which it has to effectually withstand the atmospheric and other conditions under which it may be placed.  The durability of a stone will depend, first, upon its inherent qualities which limit its capacity to withstand atmospheric and other conditions; and second, upon the atmospheric and other conditions of the immediate locality in which it is to be used.”


“The color which is most suitable or desirable in the construction of a building or a part of a building, depends mainly upon the location of the building.  The color which is actually used is determined largely by fashion or the taste of the owner.

“The predominant colors of stone are white, gray, brown, red, yellow, buff, blue, black, green and variegated.*  As a rule a stone does not have a simple, but composite color.  The color that one ordinarily sees in a stone is the resultant of the blending of the colors of the several different minerals.

(* Page 8 footnote:  Speaking from a purely scientific standpoint all of these are not colors, although they are referred to as such in this paper.)

“As a rule, the more complex the composition the greater will be the variety of colors in a rock.  The larger the mineral particles the more distinct will be the colors of the individual minerals.  On the other hand, the simpler the composition of the rock or the finer the mineral particles the more uniform will be the color.  The uniformity of color is also controlled by the uniformity in the distribution of the mineral particles in the rock.  The black nodules so common in some granites are due to the segregation in one place of mica, hornblende or some other of the ferruginous minerals.”

“On account of their homogeneous composition, the sedimentary rocks may more nearly approach a simple color than do the igneous.  However, due to the process of segregation above referred to, the sedimentary rocks may themselves have a more variegated or mottled color than the igneous.  The different shades of brown, buff, yellow, red, gray and blue of the sedimentary rocks are mainly attributable to the occurrence of the oxide, carbonate or sulphide of iron, bitumen and carbonaceous matter in the form of graphite.  The white and gray colors of marble, limestone and dolomite are attributable to the calcite and dolomite of which these rocks are mainly composed.  The translucent and white colors of some sandstones are attributable to the quartz composing the stones.  The green, gray and red colors of slate are due mainly to the iron and carbonaceous material which enter into the composition.

“In the sedimentary rock, iron may occur either as a secondary or an original constituent.  When it occurs as an infiltration product, it often serves as a cement by which the original particles are bound together.  It may also occur, however, in the shape of finely disseminated particles in the form of pyrite or hematite.  Pyrite and marcasite may also occur in small cavities in the limestone, in which case, although secondary, it does not serve as a cement.  Graphite, bitumen and petroleum frequently occur in limestone, marble and sandstone, imparting to these rocks a black, blue or grayish blue color.  Occasionally the pores of the sandstone or limestone may be filled with bitumen forming what is termed a bituminous or asphaltic limestone or sandstone.

“Among the red sedimentary rocks, there may be a wide variance in color, not only in the same quarry, but even in the same bed.  Where the color of a stone is due to the infiltration of iron oxide, there is liable to be more or less of a variegated color throughout the formation.  It is not uncommon to find red, yellow and buff colored sandstone in the same quarry.  Frequently these colors may be present in the same bed.  In some places the coloring matter occurs in regular bands, but occasionally it forms irregular, fantastic figures.  Large and small brown and red spots often occur in white sandstone, while white spots are not uncommon in the brown and red varieties.  Stone which is distinctly mottled or irregularly colored is known as variegated stone.

“With respect to color, sandstones may be classed as red, brown, white, buff, gray and black.  On the same basis, slates may be classified as red, black and green, these being the principal colors now being quarried (circa 1904).  Limestone including dolomite, is usually white or gray, but frequently has a buff color.  When impregnated with bitumen, it is black or brownish black.  Marble and onyx have a wide range in color - white, brown, red, green, black and variegated combinations of these colors being common.

“The blending of the distinct colors of the different minerals in the igneous rocks results in the production of what has been termed a composite color.  The size and distribution of the minerals, however, effect materially the color, since in some cases the crystals are sufficiently large to retain their individual tints and at a reasonable distance the stone has a mottled or speckled appearance.  At a distance, any of the granitic rocks, which may be mottled or speckled when closely inspected, appear to have a flat tint.

“Granite, which is the chief igneous rock among building and monumental stones, is ordinarily classified as red and gray.  They are, however, many shades of both colors, and whether a granite belongs to the first or second class depends mainly upon the proportions of red and white feldspar, but wherever the former is sufficiently abundant to impart a reddish tint to the rock, it is usually classified as a red granite.  In cases where the feldspar individuals are fine grained and light colored and biotite, amphibole and pyroxene are more abundant, subdued red or even a gray tint may be produced.

“Whether a gray granite is light or dark, depends upon the size of the mineral constituents and the abundance and kind of ferro-magnesian minerals present in the rock.  The lightest colored gray granites have a preponderance of white feldspar, quartz and white mica.  The dark gray granites contain a preponderance of biotite, hornblende and pyroxene, with less feldspar and quartz.

“Among the exceptional varieties of igneous rocks in use may be mentioned labradorite granite, which has a blue iridescent color, and rhyolite which is almost black.  The labradorite granite is composed mainly of porphyritic individuals of labradorite, which impart to it the iridescent color.  Rhyolite is not always black, but the color of that which is, may be mainly attributed to the semi-crystalline groundmass through which are scattered numerous small crystals of hornblende.  Some of the igneous rocks have a green color, resulting from the presence of serpentine.  The dull greenish gray color of many of the basic rocks, such as diorite, gabbro and diabase, is imparted mainly by the grayish green color of the minerals, pyroxene, amphibole and epidote, one or more of which occur as an essential constituent.

“A stone cannot be expected to retain the color which it possesses when newly quarried, either for any great length of time or under all conditions of the atmosphere.  A stone may be perfectly white when newly quarried, but a few years, or perhaps months, may change the color to a buff or streak it with irregular patches of brown.  Discolorations of this character are brought about by changes within the rock, on account of which certain ferruginous minerals are decomposed.  A light colored stone may become gray or black from exposure, through the accumulation of dust particles deposited from the atmosphere.  We therefore have changes in color brought about both by abstraction and accretion.

“Changes in color due to abstraction are brought about, mainly, by the presence within the stone of minerals which are easily decomposed.  The sulphide and carbonate of iron are often finely disseminated through a stone.  When these minerals are exposed to the atmosphere, they are decomposed, one of the resulting products being oxide of iron.  The yellow or brown oxide, known as limonite, which is thus formed, is carried in streaks over the surface destroying or marring the original color.  In some of the limestones the iron sulphide is uniformly disseminated through the rock in such minute particles as to give the stone a bluish tint.  In the quarry such a stone, near the surface, is usually altered to a buff color, while deeper down it passes gradually into the unaltered blue.  Alteration usually begins along the joint planes, passing gradually inward toward the center of the blocks.  Frequently, however, the discoloration takes place in irregular patches, giving the stone a mottled appearance.

“Blue and gray limestones and dolomites are frequently discolored by irregular efflorescent patches of calcium or magnesium sulphate.  These soluble salts are usually brought to the surface of interstitial water.  This white efflorescence is not characteristic of the dark colored rocks, although occasionally observed.  When observed on the walls of buildings it is not always due to soluble constituents in the rock, but sometimes to the composition of the mortar or cement used in the construction of the walls.

“Dark colored rocks, such as red or brown sandstone, seldom discolor, although, after long exposure to the weather, they frequently take on a lighter tint, through the loss of iron oxide, which is washed off from the surface by rain.  Decoloration also occurs in the case of some of the granites.  It takes place so slowly, however, that it is seldom an important consideration.

“The accretion of smut and dust from the atmosphere is one of the chief sources of discoloration of light colored stone used in large cities.  A stone which is roughly dressed, furnishes a multitude of places for the lodgment of dust and dirt, while one which is smooth is freer from such places.  For this reason a smooth dressed stone is less liable to discolor by dust and dirt than one which is rough dressed.  One must remember, however, that blemishes in the original color of the stone are strongly emphasized by smooth dressing and obscured by rough dressing.  These blemishes in the original color may be more unsightly than the dirt and dust, in which case it will be preferable to have the stone rough dressed.  The color of the stone depends in a measure upon the manner in which it is dressed.  This is especially true of the igneous rocks, variegated marble and some limestone.  The color of a stone is best brought out by polishing.  Hammer dressing obscures the color and is used to develop contrast with the polished surfaces.

“Stone which  is used for interior decorations suffers very little from atmospheric agencies and ordinarily the color will remain permanent.  The color of the stone used for interior decorations is mainly a question of taste.

“The predominant color of stone used for building is controlled in some measure by fashion.  A number of years ago, business blocks and residences were largely constructed out of brownstone.  At the present time (circa 1904), great quantities of light colored stone are being used and very little brownstone.  This is not due so much to the inferior quality of the brownstone as it is to the fact that people have become wearied of gazing at somber colored buildings.  The monotony in architecture would be very greatly relieved by a judicious use of both colors.  People dislike the somber character of long rows of dark colored buildings as well as the dazzling glare of a white limestone and marble.

“In the construction of business blocks in our large cities the question of color or permanence of color is scarcely worth of serious consideration.  In the midst of the business portion of a great city, white limestone and marble soon lose their original color, becoming gray and dingy from smoke and dirt.  Limestone which chances to be bituminous or contains a small amount of petroleum, catches and retains all the dust and smoke which falls upon it.  Most of the buildings in the business section of our large cities eventually become so discolored with smoke and must that one is sometimes at a loss to know whether the stone was originally dark or light colored.  On the whole, dark colored stone is preferable in a smoke and dust laden atmosphere.  However, it is thought that the chief consideration in the selection of stone to be used in the business portion of a large city should be strength and durability.

“In rural districts, or in residence and suburban parts of the city, where there is little smoke or dust, a judicious scattering of light and dark colored stone buildings will add very materially both to the appearance of the street and to the beauty of the individual dwellings.  In a clear atmosphere the color of a stone will change very little from external causes alone.

“In the selection of stone for monuments, the taste of the purchaser is the main controlling factor in the color selected.  Granite and marble are the principal stones used for monuments and as a rule contain very few minerals which will result in discoloration.  Discoloration is mainly brought about through decomposition of pyrite or marcasite.  Stones containing either of these minerals are liable to suffer discoloration when exposed to the atmosphere.

“In the selection of stone for road making, sidewalks, retaining walls, curbs, breakwaters, bridge abutments, etc., durability and not color should be the controlling factor.  In the case of retaining walls and sidewalks, color should receive some consideration owing to the fact that these constructions are partly ornamental.”

Inherent Qualities of Stone.

“The capacity of which a stone has to withstand the forces tending to destroy it is broadly known as durability.  Under durability, as used in this broad sense, must be included the strength, hardness, elasticity and stability of the mineral compound.  The durability of a stone would then depend upon its mineralogical composition and the texture or state of aggregation of the mineral constituents.  By mineralogical composition is meant the kinds of minerals of which the rock is composed and their relative abundance.  Texture has reference to the size, shape, manner of contact and arrangement of the mineral particles.  The effect of alternating heat and cold and the effect of acids depend both upon the mineralogical composition and texture.  As ordinarily defined, the specific gravity depends upon the mineralogical composition; the porosity upon the texture,; and the weight per cubic foot upon the specific gravity and porosity.  

“From the above it may be seen that an intimate knowledge of the mineralogical composition and the texture of a rock will give one, who is experienced in these matters, a very good idea of the quality of the stone.”

Mineralogical Composition.

“The ordinary building and ornamental stones, including limestone, marble, sandstone, slate, granite and rhyolite, are composed mainly of one or more of the following well known minerals, namely, quartz, feldspar, mica, calcite, dolomite, kaolin, pyroxene, amphibole and serpentine.  The relative hardness of these minerals is known and is expressed by numbers referring to a scale of hardness recognized by all geologists.  These minerals have a hardness respectively of 7, 6, 2-3, 3.5-4, I, 5-6, 5-6, 3-4. It would be interesting to know the crushing strength, tensile strength and co-efficient of elasticity of these minerals.  These constants may have been determined, although thus far any attempt to obtain them has been unsuccessful.  It is hoped that, before the completion of this report, experiments may be performed in this Bureau through which these constants may be determined.  It is also desirable that we know the heat co-efficient of expansion of each of these minerals in order to discuss intelligently the effect of alternating temperatures.  The following are the co-efficients of cubical expansion for several of the common rock forming minerals, as given in Clark’s ‘Constants of Nature,’ Smithsonian Miscellaneous Collection, Vol. XIV.:

Quartz - .000036*

Orthoclase - .000017*

Adularia - .0000179*

Hornblende - .0000284*

Beryl - .000001*

Tourmaline - .000022*

Garnet - .000025*

Calcite - .00002*

Dolomite - .000035*

(* Expansion is different along different axes.)

Quartz is perhaps the commonist and most important of the rock forming minerals.  It is the hardest but may not be the strongest or most elastic.  There is no well developed cleavage, and under ordinary conditions of temperature and pressure, it is little, if at all, acted upon by common acids.  When occurring alone or in crystal aggregates the individuals often have perfect crystals faces, but as a rock making constituent, it occurs in the form of grains which have round, oval, or irregular outlines.

“Sandstone and quartzite are composed of from 75 to 98 per cent. of quartz.  In granite, rhyolite and gneiss, quartz is a very prominent constituent.  Rocks which do not contain more or less quartz are very exceptional.

“Quartz is the most permanent of all the rock forming minerals.  It is very hard and resists to a very high degree any attempt to break or crush it.  As a result of weathering it is often broken into small particles and thus removed from the parent rock, but it is decomposed and taken into solution very slowly.

Feldspar is another very abundant mineral, which is especially characteristic of the igneous rocks.  It is slightly softer than quartz and has ready cleavages in two directions.  It is very little acted upon by the common acids under ordinary conditions of heat and pressure.  Feldspar decomposes very slowly in the quarry, but owing to the great age of some of the granite and other rocks in which it occurs, it is frequently in an advanced stage of alteration.  Owing to the perfect cleavages which it possesses, it disintegrates more readily than quartz.  The decomposed products of feldspar are objectionable only in so far as they are more readily disintegrated.

Mica is a very abundant mineral, occurring most frequently in the altered rocks known as metamorphic.  It has a very ready cleavage by which it splits into very thin plates.  These parting planes provide an easy passage for water, facilitating disintegration which generally proceeds more rapidly than in the case of  the quartz and feldspar described above.  Where mica is present in small isolated flakes, uniformly disseminated through the rock, it can scarcely effect the strength or durability of the stone.  However, where these flakes are arranged in layers, along the planes of sedimentation, they give the stone a capacity to part, which will necessarily weaken it.  The mica, unless it occurs in large individuals or flakes clustered together, will disintegrate scarcely less rapidly than quartz or feldspar.  Mica decomposes very slowly through chemical agencies.

Calcite.  Calcite is almost as abundant a rock forming constituent as quartz, although it is less permanent at the surface of the earth.  The hardness and probably the strength and durability of calcite are all less than quartz.  It possesses perfect cleavages in three directions on account of which it disintegrates quite readily.  It is easily soluble in carbonated waters and is readily acted upon by cold dilute hydrochloric acid.  Calcite is an essential constituent of all limestones, marbles and sandstones.  It also enters into the composition of many of the igneous rocks, being frequently an alteration product of other minerals.

“Dolomite differs from calcite, mainly in having a somewhat greater hardness and in the fact that it dissolves less readily in cold dilute hydrochloric acid.  It disintegrates almost as readily as calcite, although taken into solution somewhat more slowly.  It is one of the most abundant constituents of magnesian limestone, frequently composing as much as 95 per cent. of the rock.

Kaolin is an abundant constituent of slate and a lesser constituent of sandstone, limestone and altered rocks of the granitic type.  It is mainly of secondary origin, being usually a decomposition product of feldspar.  It is one of the softest minerals, has a perfect cleavage and disintegrates readily.  It is not acted upon by the common acids except under very favorable conditions.

Pyroxene is one of the less important minerals of building stone.  It occurs mainly in the granites and allied igneous rocks.  It cleaves perfectly in two directions and disintegrates slowly through mechanical abrasion.  It gradually decomposes in the presence of water altering to chlorite, calcite and epidote.

Amphibole is an essential constituent of many granites, but is most abundant in the basic igneous rocks.  It also occurs in many schists and altered sedimentaries.  Under ordinary conditions, at the surface of the earth, it decomposes very slowly.

Serpentine occurs in certain green colored rocks such as verde antique, and is usually an alteration product of olivine.  Under ordinary conditions it is a stable chemical compound, but owing to the irregular cracks which it contains, it is seldom used in places exposed to the atmosphere.

“Among the accessory minerals common to building stones may be mentioned pyrite, marcasite, hematite, magnetite, graphite and bitumen.  Hematite and magnetite are not considered harmful constituents.  The red, brown or yellow color of stone is usually attributable to the presence of these constituents.  graphite frequently occurs in limestones, marbles and sandstones and is not an objectionable constituent, except where it occurs in large quantities.  Bitumen occurs mainly in limestones and sandstones and is objectionable chiefly on account of the discoloration which is apt to result from the accumulation of dust and dirt from the atmosphere.

“Pyrite and marcasite decompose quite readily in the presence of moisture, resulting in the production of yellow iron oxide which, in the case of light colored stone, is apt to result in objectionable forms of discoloration.  The decomposition of pyrite in limestone or dolomite also results in the production of magnesium and calcium sulphates which are brought to the surface and deposited in the form of a white efflorescence.

“The shattering of rock when subject to high temperatures has been attributed in certain cases to the occurrence of gaseous inclusions in the minerals.  To what extent such inclusions assist in the destruction of rock when subjected to a high temperature is not known.  It is probable, however, that a temperature which would make these gases active agents of disintegration would destroy the rock through the unequal expansion of the mineral particles.

“A stone is an aggregate of minerals and the hardness, strength, elasticity and capacity to withstand chemical action and alternating temperatures are in part controlled by the relative abundance of the different mineral constituents.  Provided the size, shape and arrangement of the individuals are constant, the hardness of a stone will increase or decrease with the percentage of quartz which it contains.  So in the case of the strength and elasticity of a stone, it will increase as the minerals in which these properties are best developed are increased.

“It must be understood, however, that the hardness, compressive strength and elasticity in any mineral may not occupy the same relative position as in other associated minerals.  An increase in the percentage of one mineral may increase the hardness of the rock at the expense of strength and elasticity, and vice versa.  Finally it must be borne in mind that elasticity, hardness and strength are not controlled entirely by the relative abundance of the different mineral constituents.  The size, manner of contact and arrangement of the mineral particles are important factors in determining the qualities of any stone.”

Texture or State of Aggregation.

“In speaking of the texture of a rock, one has reference to the size, shape, manner of contact and arrangement of the mineral particles.  Upon the arrangement of the mineral particles, also depend certain structures in the rock.

“The size of the particles affects the manner in which the stone weathers.  In case the mineral particles are large, those that are soft disintegrate most readily, often leaving small depressions which give the surface a pitted appearance.  Cleavage cracks are more liable to open up in the large than in the small minerals, thereby hastening decomposition.  Fine grained rocks may have correspondingly small pore spaces, although the size of the pores is mainly controlled by the shape and manner of contact of the grains.

“The shape and manner of contact of the mineral particles influence the strength and durability of the stone as much, if not more, than any of its other qualities.  In a stone in which the grains are close fitting, adhesion is increased and the pore space decreased.  Grains having irregular outlines usually interlock in the manner of dove-tailing, increasing the strength and lessening the pore space.  Upon the arrangement of the grains depend the laminated, schistose or cleavage structures in rocks.  The capacity which a rock has to part more readily in one direction than in another, is frequently due to the arrangement of mica or other minerals, having their longer axes in a common direction.  The perfection of the parting capacity is influenced by the abundance and size of the grains which have thus arranged themselves.

“The percentage of pore space and the size of the pores are controlled by the size, shape, manner of contact and arrangement of the grains.  This applies to both igneous and sedimentary rocks, in the latter of which the particles of cement binding the original grains together are considered as grains.  The openings in rocks have been divided into three classes.  The first are the small interspaces that exist between the grains of a rock, known as pore spaces; the second are those openings which form along bedding, jointing and fissile planes, known as sheet openings; the third are those openings which have resulted from the removal of several or many individual grains and are commonly known as cavities, caves or caverns.

“Pores differ very greatly in size, depending upon the size and shape of the original particles composing the rock, and the extent to which the interstices have been filled with secondary material.  These pores are conceived of as being connected in such a manner as to allow water to flow from one part of the formation to another.  The pores in a rock are not all of the same size, although they may have a general uniformity in size.  Pore spaces in rocks have been classified according to size into super-capillary, capillary, and sub-capillary.*  The water which fills the capillary pores is known as the water of saturation.  Openings of this class are over .00002 centimeter in diameter.  Sub-capillary pores are conceived to be of such a size, smaller than .00002 centimeter in diameter, as to contain only the water of imbibition.  If a rock containing pores is allowed to drain off naturally, a part of the water will escape, but another portion will remain adhering to the grains.  This is known as the water of imbibition.  Many rocks contain pores both of capillary and sub-capillary size.  In fact, it is thought that there are few building stones which do not contain some pores of sub-capillary size.

(* Page 18 footnote:  ‘Metamorphism of rocks and rock flowage,’ C. R. VanHise, Bulletin of the Geological Society of America, Vol. 9, p. 272.)

“As in the case of pores, Van Hise has classified sheet openings which occur along jointing, bedding or other fissile planes as capillary and sub-capillary, including in the latter all such as are less than .00001 centimeter in thickness.  The openings of the third and last class, comprising caves, cavities and caverns, occur mainly in Limestone and dolomite.  They also occur infrequently in rocks which are less readily soluble.”

External Causes of Decay.

“It is very important in the selection of a stone to know the climatic conditions under which it is to be placed when in use.  A climate which is subject to rapid changes in temperature, or one in which the atmosphere is moist or humid, promotes decay.  A climate in which the temperature is uniform and always above the freezing point, and one I which the atmosphere is dry, is conducive of permanence and stability.  It requires a stone of the most enduring qualities to withstand the changes of a moist temperate climate, in which there are long seasons of alternate freezing and thawing, short hot summers and cold winters.  It is not the inherent qualities of the stone, such much as the warm dry atmosphere, to which the excellent condition of the monuments of Rome and Egypt is attributable.  These monuments, after centuries of exposure, are still in an excellent state of preservation.  After only forty years of exposure in Paris, the obelisk of Luxor which stood for centuries in Egypt without any perceptible deterioration, is now filled with small cracks and blanched.*  The same is true of the obelisk in Central Park, New York, from which many pounds of small fragments have fallen.**

(*  Page 19 footnote:  A. A. Julien, 10th Census, Vol. V., p. 370.)

(** Page 19 footnote:  Referred to J. C. Smock, Bulletin New York Museum, Vol. II, No. 10, p. 385.)

“Apparently some stone which has remained unchanged under certain climatic conditions in the quarry, when removed and used under different climatic conditions will deteriorate.  Stone is not as sensitive to the atmospheric and climatic changes as man, yet in a measure stone seems to endure best in its native climate.  The minerals seem to adjust themselves, in some way, to certain conditions and when removed the stone will deteriorate through the attempt at readjustment.

“Changes in a rock are brought about in two ways.  First, mechanically, by disintegration, and second, chemically by decomposition.  Mechanical disintegration refers to the crumbling of the rock into sand or powder.  This may be brought about through chemical changes, but it is usually a result of friction or pressure, by which the adhesion between the particles or the cohesion within the particles is overcome.  Decomposition implies a chemical change, through which the identity of the mineral substance is lost.  When decomposition takes place, the mineral particles are destroyed by being broken up into compounds.

“The following is a brief classification of the important agents of disintegration and decomposition:

I.  Agents of Disintegration.

A.  Temperature Changes.

  1. Unequal expansion and contraction of the rock and its mineral constituents.
  2.  Expansion occasioned by the alternate freezing and thawing of water contained in the stone.

B.  Abrasion.

  1. Water.
  2. Wind.
  3. Feet.

C.  Growing Organisms.

D.  Careless Methods of Working and Handling Stone.

II.  Agents of Decomposition.

A.  Water-Solvent Action.

B.  Carbon Dioxide.

C.  Sulphurous Acids.

D.  Organic Acids.”

Agents of Disintegration.

Temperature Changes. - Through changes in temperature a stone may be injured in two ways, - first, by the unequal expansion and contraction of the rock and its mineral constituents, and second, through expansion due to the alternate freezing and thawing of the water contained in the stone.

Unequal Expansion and Contraction of the Rock and Its Mineral Constituents. - Stone has a very low heat conductivity.  A slab a few inches in thickness may be heated on one side to a temperature so high that it will not bear handling, while the other side of the stone may be comparatively cold.  Mr. W. H. Bartlett* has determined experimentally the exact expansion of different kinds of stone.  The following are the results which he obtained:

(* Page 20 footnote:  Refer to American Journal of Science, Vol. XXII, 1832, p. 136.)

Granite - 000004825 inch per inch for each degree F.

Marble - .000005668 inch per inch for each degree F.

Sandstone - 000009532 inch per inch for each degree F.

“In this latitude the diurnal changes in temperature are often as much as 50° Fahrenheit.  The annual variation exceeds 100° Fahrenheit.  A difference of 100° Fahrenheit would make a difference of about sixteenths of an inch in a sheet of granite 100 feet in diameter.

“The difference in the rate of expansion of the different minerals initiates stresses in rocks having a heterogeneous composition, which tend to separate the individual minerals form one another.  Whenever a stone is heated, each particle presses against its neighbors with unequal stresses in different directions.  When it is cooled, stresses are set up which have a tendency to pull the individual apart.  As a result of this expansion and contraction, the rock is weakened and in time small cracks are often produced into which water may percolate or roots descend.

“Between the different laminae or hypothetical layers of rock, which are near enough to the surface to be affected by the atmosphere, there is an unequal expansion and contraction.  The layer nearest the surface suffers the greatest changes in temperature, while each succeeding layer is less affected.  Finally a point is reached where the rock, the year around, is not affected by the temperature conditions at the surface.  In some regions owing to the rapid changes in temperature, forces are continually at work tending to separate the surface layer from that immediately underneath it.  Owing to their heterogeneous mineralogical composition and the interlocking character and difference in size of the grains the igneous rocks are more liable to injury from diurnal changes of temperature than are the sedimentaries.

“George P. Merrill* cites an instance in Montana where he found ‘Along the slopes and valley bottoms, numerous fresh concave and convex chips of andesitic rock which were so abundant and widespread as to be accounted for only by the diurnal temperature changes.  During the day the rocks became so highly heated as to become uncomfortable to the touch, while at night the temperature fell nearly to the freezing point.  Livingston reports that the temperature of the rock surfaces in Africa frequently rises as high as 137° Fahrenheit.  During the night time, the rocks cool off so rapidly as to split off fragments weighing as much as 200 pounds.

(* Page 21 footnote:  Rock Weathering and Soils, p. 181.)

“The effects of exposure to the weather upon stone in the walls of buildings exposed to the direct rays of the sun, may be observed in most large cities.**  The disintegration observed in these places may be best accounted for by the diurnal temperature changes.  The movements due to temperature changes are necessarily small, but when they continue through centuries of time they must result in the eventual disintegration of the stone.

(** Page 21 footnote:  Rapid changes in temperature frequently result from rain falling on surfaces which are highly heated.  This has frequently been know to split stone.)

Expansion Occasioned by the Alternate Freezing and Thawing of the Included Water. - In this latitude the effect of the alternate freezing and thawing of a rock saturated with water is much greater than that of diurnal temperature changes.  Geikie has graphically described the expansive force of freezing water ‘As being equal to the weight of a column of ice a mile high or a little less than 150 tons to the square foot.’  In the form of ice at 0° centigrade, one centimeter of water at 9° centigrade occupies 1.0908 centimeters.  The damage done through the solidification of confined water is due to this expansion of about one-tenth.

“In a consideration of the effects of the freezing and thawing of included water one must clearly distinguish between pores and fissile planes.  Openings and hollow paces are everywhere present in the rock, and through these the water finds its way into the deeper portions of the earth.  The water of saturation which is contained in the large pores of a rock, is given off with comparative readiness, but that which is contained in the pores or sheet openings of sub-capillary size is retained with great tenacity.  It is easy to understand how the particles composing a rock may be fitted so closely together that these openings will be mainly of sub-capillary size.  Most of the water contained in a rock having such pores is the water of imbibition, and will be given off very slowly, increasing the danger from freezing.  In general it may be said that the danger from freezing will increase as the pores approach in size those of sub-capillary dimensions.  In a nonabsorbent rock, there will be vastly greater danger from the freezing of water which has collected in sheet openings owing to the slowness of drainage.  Changes in temperature may easily come about before the water has had an opportunity to escape.  In a rock containing capillary pores the drainage is much more rapid and the water in the cracks is much more quickly dissipated.  A saturated stone which contains large irregular solution cavities and in which the pores are chiefly of sub-capillary size is in very greater danger from freezing.  The drainage of the water contained in the cavities through the pores is very slow and a sudden change from thawing to a freezing temperature will prove disastrous.

“The pores in two stones, which have a capacity to absorb equal amounts of water, may be very different in size.  The stone in which the pores are minute will be in much greater danger from alternate freezing and thawing than the one in which the pores are large.  In equally saturated rocks, having pores of the same size, the one having the greater percentage of pore space will be in the greatest danger from alternate freezing and thawing.  The effect of freezing will also be conditioned by the percentage of the pore space that is filled with water.  A rock which is two-thirds saturated will suffer greater injury from freezing than one which is only one-third saturated.  If none of the pores are more than nine-tenths filled with water, there will be no danger from freezing, because the increased bulk resulting from solidification will no more than fill the spaces between the grains.

“The amount of water which the pores contain at a given time depends (1) upon the amount of water initially absorbed; (2) the time that has elapsed since the water was absorbed; (3) the size of the pores; (4) the position of the stone; and (5) the condition of the atmosphere.  Only in exceptional cases is the stone in the walls of a building saturated.  If the pores are capillary size, the water of saturation will, as a rule, be quickly removed except below the water line.

“From the above it appears that estimating the danger from freezing and thawing, the size of the pore spaces demands first consideration, because this controls the rate at which the interstitial water is given up.  The next important consideration is the amount of water contained in each of the pores at the time of freezing.  The third and least important consideration is the total amount of pore space.

“T. S. Hunt in ‘Chemical and geological essays,’ says:  ‘Other things being equal, it may properly be said that the value of a stone for building purposes is inversely as its porosity of absorbing power.’  Various authorities have quoted this statement saying in general:  ‘Other things being equal, the more porous the stone the grater the danger from frost.’  A common mistake is to estimate the danger of freezing from the capacity which a stone has to absorb water.  The durability of a stone is constantly being estimated from its ratio of absorption.  Unfortunately these estimates are very misleading.  Although one should know the capacity which a stone has to absorb water, in making an estimate of durability, he should give first consideration to the size of the pores.

“Quarrymen and contractors are familiar with the injurious effects of the freezing of the interstitial water known as ‘quarry water.’  Contractors frequently refuse to accept stone, especially sandstone, which has not been seasoned before being exposed to the action of frost.  Quarrymen sometimes flood their quarries during the winter months that the stone immediately at the surface may be protected.

“Bedding, jointing and other fissile planes permit a freer circulation of water than the pores in the rock.  The water from rain and melting snow, which collects in cracks, crevices and pores at or near the surface is carried away much more slowly than it accumulates.  In case the temperature is fluctuating between freezing and thawing, the water in these crevices will be alternately in a liquid and solid state.  As the water freezes and melts again and again, the walls of the cracks are shoved farther and farther apart.  The ice acts as a wedge, which automatically adjusts itself to the size of the crack, until the opening is sufficiently wide and deep to permit a free passage of the water.  Besides enlarging and extending the cracks and crevices, the freezing of the water exerts a pressure, on account of which the stone is itself materially weakened.

“One must not confuse the danger from the freezing of water which collects along parting planes with the danger attendant upon the freezing of water which fills the pores.  Rocks, in which bedding, jointing and other fissile planes occur, are in greater danger from alternate freezing and thawing than the compact thoroughly homogeneous rocks which have no bedding other parting planes.

“One of the chief causes of the deterioration of building stone, and more especially stone which is bedded or otherwise laminated, is the alternate freezing and thawing of the included water.  The use of stone which is laid on edge instead of on the bed, and that which has not been properly seasoned, has frequently been accompanied by disastrous results.  Stone which is frozen before being properly seasoned is weakened throughout its mass, while that which is laid on edge frequently deteriorates through exfoliation or scaling.  The most dangerous place for a stone in a building is at the water line, where saturation is most common and alternate freezing and thawing most frequent.  In the case of bridge abutments and retaining walls, the conditions are even more severe than at the water line in a foundation wall.  The courses of stone at the water level in bridge abutments are frequently badly shelled and broken, while the stone above and below may be entirely uninjured.  Retaining walls are frequently in a very dilapidated condition after they have been constructed comparatively few years.  The water which seeps into the ground above a retaining wall often issues through cracks and crevices in the stone.  Under certain atmospheric conditions the water will freeze as it reaches the surface, forming ice wedges which push the laminae of the rocks apart.

“Sedimentary rocks, owing to the frequency with which they have parting planes, are, as a class, more apt to suffer from alternate freezing and thawing than the igneous rocks.  Sometimes, however, the sedimentary rocks are as free from parting planes as the igneous, and are accordingly in as little or even less danger from freezing.

“Very little attention need be given to caves, caverns and cavities.  Cavities are of common occurrence in both sedimentary and igneous rocks, although more abundant in the former.  In practice the danger from freezing is not materially increased by their presence, owing to the fact that they are seldom filled with water when near the surface.  As the cavities approach capillary pores in size they increase the danger attendant upon freezing, especially if the only means of drainage be through very minute pores.  It may be said that cavities are most objectionable when they occur in stone in which the pores are very minute.  Cavities weaken the rock slightly and often produce a roughness at the surface.

“If the foregoing is accepted, we must conclude that an ordinary well cemented sandstone, which is free from parting planes or stratification, and in which the pores are of capillary size, is best suited to withstand alternate freezing and thawing in the alls of a building; it being assumed that the strength of the stone is sufficient for the position which it occupies.

Mechanical Abrasion. - The comminution of the rocks mechanically, or through abrasion, is one of the most important processes in the wasting away of the land surface.  However, the part which it plays in the destruction of buildings and other forms of masonry construction, is not nearly as important as that of other agencies.

“Mechanical abrasion is accomplished mainly by wind, running water and the shuffling of feet.  The rain which beats against a stone wall may overcome the adhesion between the rock particles, separating them from one another and carrying them away.  As these particles are carried down the side of the building, they, in turn, may loosen other particles, and so on until the ground is reached.  Drifting sand, which is such an important agent of disintegration in the arid regions, plays a very unimportant part in the temperate zone.  It contributes an almost insignificant part of the process of disintegration.  Professor J. C. Smock, in his report on the building stones of New York, mentions the fact that the ground glass character of many of the window panes, in some of the older houses of Nantucket, is due to drifting sand.  Drifting sand in some of the older eastern cemeteries has removed the polish, and in some cases even the lettering on the monuments.

“Stone, which is used for sidewalks, floorings, steps, etc., is in a position where it is subject to the abrading action of feet which are constantly passing over its surface.  There is a great difference in the capacity which different stones possess to withstand abrasion.  In every city one finds sidewalks and pavements which are badly worn by the constant shuffling of feet over their surfaces.  The steps approaching the capitol in Jefferson City are badly worn through this agency.

Growing Organisms. - Stone in the quarries and elsewhere is frequently covered with a growth of lichens and algae.  Trees growing on the hillsides often send their roots deep into crevices and cracks and by their growth and expansion break off huge blocks of stone from the parent mass.  Occasionally in very soft, porous rocks the writer has observed the finer rootlets, ramifying through the body of the rock itself.  Organic acids, produced by the decaying plants, aid in the decomposition of the rock.  Lichens often cover the natural rock exposures, forming a mat, which exerts both a protective and destructive influence.  They serve to protect the rock from the atmosphere, while the acids formed through their decay and the mechanical action of their rootlets, penetrating between the grains, result in slow disintegration.  The damp parts of a wall are frequently covered with green algae, which cause discoloration through their own decay and the accumulation of fine dust particles from the atmosphere.  Creeping vines, such as ivy, serve as picturesque coverings to the walls of a building, although they are undoubtedly somewhat harmful to the stone.

Careless Methods of Working and Handling. - The rapidity with which the atmospheric agencies cause disintegration is often greatly accelerated through the weakening of a stone by improper methods of quarrying, and carelessness in cutting, carving and laying the stone in the building.  Improper methods of quarrying and handling have probably resulted in shortening the life of the stone used in many buildings at least one-half.

“Dynamite is sometimes used to move stone in a quarry, from which it is expected to obtain dimension stone for building purposes.  Heavy charges of powder not only destroy a large quantity of stone, but they also shatter the cement which binds the particles together and produce incipient joints, which lessen both the strength and durability of the stone.  The incipient joints not only weaken the rock, but facilitate the entrance of water, with the attendant dangers from alternate freezing and thawing.  This method of quarrying not only lessens the value of the saleable stone, but frequently destroys hundreds of tons of stone which would otherwise be marketable.  Splitting stone, by striking continuously along one line with heavy hammers and sledges, injures it in the same manner as heavy blasting.

“These injuries to the stone, brought about by quarrying, may be avoided by exercising ordinary care.  Quarrymen, as far as possible, should take advantage of the natural joints.  Whenever it becomes necessary to use powder, the Knox system of small charges properly distributed, is thought to be the least injurious.  In working sandstone and limestone on an extensive scale, the channeling machine is considered the best method of reducing the stone to dimensions that can be easily handled.

“During the process of seasoning, the quarry water comes to the surface, evaporates and deposits mineral matter, which frequently forms a crust on the surface of the stone.  This crust is usually formed entirely by the evaporation of the original interstitial water.  It is thought, that through saturation with water containing the same mineral salts in solution and by subsequent evaporation, an almost appreciable amount of mineral matter may be deposited at the surface, as in the case of the evaporation of the original interstitial water.  The water of imbibition which has been defined above, probably carries a much greater percentage of mineral matter in solution than the water of saturation.  The water of imbibition is the last of the quarry water to leave the stone and its complete removal will not be accomplished until the rock has been thoroughly seasoned.  In case a stone is of such a nature that it must be seasoned before being placed in the wall, it should be first cut, dressed and carved.  When first quarried a stone often works much more readily than after it has been seasoned.  For this reason, as well as from the standpoint of their future durability, some stones should be dressed before being placed in a wall.  After the crust has once formed, it should not be broken, because the softer rock underneath, when exposed at the surface, will disintegrate much more rapidly.  It is evident from these observations that the time of cutting and dressing a stone may influence its life to such an extent, as to make it important that it should be finished, ready for laying in the wall, before being thoroughly seasoned.

“The life of a stone is also influenced in a small way by the manner of dressing.  A polished surface sheds water more quickly than a rough one.  A stone with rough surfaces has many crannies and crevices in which the water may collect, and from which it may be absorbed.  Hammer dressed sandstone is liable to disintegrate faster at first than that which has been sawed, due to a weakening of the cement by the impact of the hammer.  Polished and sawn surfaces, as a rule, shed water more readily than those that are hammer dressed.  The rock faced and hammer dressed blocks, on account of their rough exterior, absorb a considerably larger percentage of the water which falls on their surfaces, than the polished and rubbed surfaces.

“The exfoliation of sandstone has been attributed mainly to the laying of stone on edge instead of on the bed.  Owing to the greater readiness with which stratified and schistose rocks can be dressed along the bed, they are frequently laid on edge.  This has been practiced more especially in veneer work, but is occasionally met with in heavy masonry.  Where the parting planes are normal or inclined to the surface of the earth, they admit the passage of water more readily than where they are parallel.  If a block of stone is laid on edge in a wall, the danger from freezing of the included water is greater than if it were laid on the bed.  The pressure required to split off laminae of stone which is laid on edge, is ordinarily much less than in case of stone which is laid on the bed.  The force occasioned by the freezing of water, which collects between the layers, is augmented by the superincumbent pressure of the wall.  Water is less apt to penetrate along the parting planes in case the stone is laid on its bed, and even though it should penetrate with equal freedom in this position, the superincumbent pressure of the wall would tend to force the expansion in directions of least resistance, which are parallel to the bedding.

“In case the stone is laid on edge, the different blocks will emphasize more strikingly the differences in the texture than if it were laid on the bed.  the different blocks will, as a whole, exhibit different rates of wear, instead of the minor inequalities usually shown by the different laminae when the blocks is laid on the bed.  The only safe rule to follow, in important structures, is to avoid laying any stone on edge which shows stratification or schistosity.  In this position the stone is usually weaker, promotes a more ready absorption of water, and is in grater danger from alternate freezing and thawing.”

Quarrying Industry of Missouri 1904 continued on Page 1 2 3 4 5 6 7

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